<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>输入检查算法</title>
	</head>
	<body>
		<script>
		function boo(bool) {
		    // What is the new fad diet for ghost developers? The Boolean.
			if(typeof bool==="boolean")
			    return true;
			else{
				return false;
			}
		}
		
		document.write(boo(false));	
		</script>
	</body>
</html>
